- #1
AcousticBruce
- 37
- 0
Hello folks. I pulled out my algebra and trigonometry book that I kept from college (that I never ended up going). I am brushing up with algebra right now and this is something that stumped me. If you do not mind, I would love to learn how I can think differently in order to complete this problem. Thank you.
## a^6-b^6 ##
I immediately see that I can do a difference of cubes like this...
## (a^2)^3-(b^2)^3 ##
and this leaves...
## (a^2-b^2)(a^4+a^2b^2 + b^4 ) ##
I am left with a difference of squares so I expand farther...
## (a-b)(a+b)(a^4 + a^2b^2 + b^4) ##
I thought I was done, though something did look fishy about the trinomial and here is what the solution manual has...
## (a-b)(a+b)(a^2 - a*b + b^2)(a^2 + a*b + b^2) ##
I was completely confused by the answer so I factored the last trinomial with a ti-89 and sure enough, it expanded farther.
Why does ##(a^4+a^2b^2 + b^4 ) ## factor into ##(a^2 - a*b + b^2)(a^2 + a*b + b^2) ##
How can I look at this and understand why?
## a^6-b^6 ##
I immediately see that I can do a difference of cubes like this...
## (a^2)^3-(b^2)^3 ##
and this leaves...
## (a^2-b^2)(a^4+a^2b^2 + b^4 ) ##
I am left with a difference of squares so I expand farther...
## (a-b)(a+b)(a^4 + a^2b^2 + b^4) ##
I thought I was done, though something did look fishy about the trinomial and here is what the solution manual has...
## (a-b)(a+b)(a^2 - a*b + b^2)(a^2 + a*b + b^2) ##
I was completely confused by the answer so I factored the last trinomial with a ti-89 and sure enough, it expanded farther.
Why does ##(a^4+a^2b^2 + b^4 ) ## factor into ##(a^2 - a*b + b^2)(a^2 + a*b + b^2) ##
How can I look at this and understand why?
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